The present invention relates to a direction-indication-lamp control apparatus for a vehicle for turning on a turn lamp disposed at each of the left-hand and right-hand sides of the vehicle as a lamp in a daytime travel.
There are various proposals made to enhance safety of the vehicle by illuminating the space in front of the vehicle in the daytime travel. In this case, when a head lamp of the vehicle is used as the lamp in the daytime travel, it is necessary to provide the vehicle with means for reducing the luminous intensity of the head lamp, because the head lamp is too bright in the daytime. As the known luminous intensity reduction means, the following means are hitherto used: the head lamp is lighted by PWM (pulse width) control. As another example, right and left head lamps are connected in series to each other. As still another example, a resistance is connected in series to the head lamps.
On the other hand, the luminous intensity reduction means is not required in the case where turn lamps disposed at the left-hand and right-hand sides of the vehicle are used as the lamp in the daytime travel. Direction-indication-lamp control apparatuses for a vehicle using the turn lamp used as the lamp in the daytime travel are disclosed in the specification of Japanese Utility Model Publications Nos. 5-29947 and 5-29948.
FIG. 6 schematically shows the construction of the direction-indication-lamp control apparatus for a vehicle disclosed in Japanese Utility Model Publication No. 5-29947. In the direction-indication-lamp control apparatus, when the ignition switch 101 is turned on, an electric power is supplied to the turn lamps 105, 106 from the battery 102 through the relays 103, 104 respectively to turn on the turn lamps 105, 106.
When the turn switches 107, 108 are switched to the left (the side at which the left-hand turn lamp 105 flashes on and off) or the right (the side at which the right-hand turn lamp 106 flashes on and off) or when the hazard switches 109, 110 are switched to turn them on, the daylight cancellation portion 111 actuates the relays 103, 104 to switch the contact. At this time, the flasher portion 112 outputs a flashing-signal to flash the corresponding turn lamp.
The construction allows the turn lamp disposed at the left-hand and right-hand sides of the vehicle to serve as the lamp in the daytime travel when the ignition switch is ON.
The direction-indication-lamp control apparatus for a vehicle disclosed in Japanese Utility Model Publication No. 5-29948 has the flash detection means for detecting a flashing signal outputted from the flasher portion 112, instead of the daylight cancellation portion 111 to switch the contact of the relays 103, 104, based on an output of the flash detection-means.
According to the control apparatus disclosed in the specification of U.S. Pat. No. 4,723,095, the turn lamp disposed at each of the left-hand and right-hand sides of the vehicle is turned on as the lamp for the daytime travel when the ignition switch is turned on.
In the art of any of the above-described publications, when the turn switch is switched to the left or the right in the state where the turn lamp disposed at each of the left-hand side and the right-hand side of the vehicle is turned on as the lamp in the daytime travel, one of the turn lamps flashes on and off in correspondence to the switching operation, and the other turn lamp is turned off.
It is preferable to keep the turn lamps lighting as the lamp in the daytime travel. Therefore, it is not preferable that the switching operation of the turn switch causes one of the turn lamps to be turned off.
It is an object of the present invention to use left-hand and right-hand turn lamps as lamps in a daytime travel of a vehicle and. flash one of the turn lamps corresponding to an operation of a turn switch and keep the other turn lamp turned on.
According to the direction-indication-lamp control apparatus of the present invention, when a requirement of a daytime travel is satisfied and a requirement of flashing a left-hand turn lamp and a requirement of flashing a right-hand turn lamp are not satisfied, the left-hand turn lamp and the right-hand turn lamp are turned on as the lamps in the daytime travel. When a left contact of a turn switch is turned on in this sate, the requirement of flashing the left-hand turn lamp is satisfied. Thus the state of the left-hand turn lamp changes from the turn-on state to a flashing state, whereas the right-hand turn lamp continues the turn-on state. On the other hand, when a right contact of the turn switch is turned on, the requirement of flashing the right-hand turn lamp is satisfied. Thus the state of the right-hand turn lamp changes from the on-state to the flashing state, whereas the left-hand turn lamp continues the turn-on state. In this manner, it is possible to flash one of the left-hand and right-hand turn lamps and keep the other turn lamp turned on in correspondence to a switching operation of the turn switch to the left or the right by separately determining the requirement of flashing the left-hand turn lamp and the requirement of flashing the right-hand turn lamp and then turning on/flashing the left-hand turn lamp and the right-hand turn lamp independently.
The signal indicating the requirement of the daytime travel includes a signal outputted from an ignition switch and a signal outputted from a head lamp switch. The signal indicating the requirement of flashing the left-hand turn lamps includes a signal outputted from the turn switch turned to the left and a signal outputted from a hazard switch. The signal indicating the requirement of flashing the right-hand turn lamps includes a signal outputted from the turn switch turned to the right and a signal outputted from the hazard switch.
First through fourth relay means are used to turn on/flash the left-hand turn lamp and the right-hand turn lamp. Each of the third and fourth relay means can be constituted of a relay means of make-and-break type. In this case, at most, two relay means are operated to turn on/flash the left-hand turn lamp and the right-hand turn lamp. Thus it is possible to reduce the quantity of heat generated by the operation of the relay means.
It is possible to use four relay means of the same type (for example, one-make type) to turn on/flash the left-hand turn lamp and the right-hand turn lamp.